Circuit breaker



June 30, 1942. w. H. FRANK CIRCUIT BREAKER Filed Nov. 8, 1941 2 Sheets-Sheet 1 llb mnwnm.

X ATTORNIX June 30, 1942. w. H. FRANK CIRCUIT BREAKER Filed Nov. 8, 1941 I 2 SheetsSheet 2 Fig 4 INVIWTM.

ATTORNE'Z Patented June 30, 1942 CIRCUIT BREAKER William H. Frank, Detroit, Mich, assignor to Bulldog Electric Products Company, Detroit, Mich., a corporation of West Virginia Application November 8, 1941, Serial No. 418,419

16 Claims.

This application relates to circuit breakers.

A principal object of the present invention is to provide a circuit breaker employing a single spring for providing all spring functions desired in a circuit breaker and wherein a novel interaction of operating parts of the circuit breaker is obtained through the relative positioning of the parts and the use of that single spring.

For an understanding of the circuit breaker herein disclosed, reference should be had to the appended drawings.

In these drawings:

Figs. 1, 2, and 3 show the device in closed circuit (on), open circuit (off), and overload released or tripped positions, respectively.

Fig. 4 is a plan view.

Fig. 5 is a section view.

Fig. 6 is a section view, with section lines omitted f or the sake of clarity.

The circuit breaker herein disclosed comprises a two part or split casing Ill having a slot H in which moves a manually movable, hollow, open bottomed, contact support 12, pivotally mounted in recesses l3 on the sides of the casing by pivot lugs or stub shafts 14. Inner wall slots I5 of support l2, on its opposite sides and alined with its lugs 14, mount a shaft [8 which is disposed in a hole I! of a movable contact arm l8 having a contact 19 for engaging a stationary contact 20 mounted on a terminal connector.

A spring 2! has its upper end 22 simultaneously engaging edges 23a. and 23b of lugs or arms 24a and 24b of the support and contact arm respectively, these defining an angle whose apex is designated A, and which is spaced radially from either axis. The lower end of the spring seats in a notch of a block part 25 of the lower wall of the casing.

Integrally secured to the arm l8, near contact l9 and pivot I6 is a bimental strip or latch 25 connected by a flexible lead 21 to a terminal connector 28. The free end of the latch is bent to form a latching portion 29 cooperating with the support 12 for releasably interlatching the contact and the support at point 29. A sloping wall of the block 25 forms a stop 30 for the contact end of the contact arm. Ends Ila and Nb of slot H form eventual stops for support i2, and parts 20 and 30 are stops for arm l8.

Pin 3| in the portion 32 of the arm slidably engages the inner walls of the support for guiding the latching end of the arm with respect to the support.

Operation On.-In the closed circuit (on) position indicated, (with latch holding), spring 2!, disposed within the apex A formed by the meeting of the non-radial edges 23a-23b of lugs Lia-24b of the contact and support, biases both the contact and support to rotate in opposite rotative directions about their axes to maintain the support at rest in the closed circuit position, with end I la of slot H of the upper wall of the casing eventually stopping the support; contact pressure is maintained at contact Iii-20, with contact 2!! stopping the arm l8. Support slots l5 permit movement of arm l8 against the spring force if the handle is forced too far.

On to oif.-Figs. 1 to 2: When the support is moved manually to the position of Fig. 2, the contact arm moves with it to the open circuit position of Fig. 2. In the early part of the on to of? stroke or circuit opening stroke, a compressive force is imparted against the spring 2|; the line of action of spring 2|, which had been to the left of the axes is swung to the right of the axes; after that line crosses the axes, the spring tends to relieve itself of part of the compressive stress and tends to snap the parts to the position of Fig.2. Parts 30 and end Nb of the slot H form stops for the parts 18-49.

Off to on.-Fig. 2 to Fig. 1: When the support I2 is swung from the position of Fig. 2 to Fig. 1, manually, the support and arm move as a unit to swing the line of action of the spring from the right of the axes to the left thereof, first stressing that spring, and after the line of the spring crosses the axes, the spring relieves itself of part of its stress and, snaps the contact arm to the closing position of Fig. 1. Parts 20, iatgld ieznd Ila of slot ll provide stops for parts During manual actuation the support and arm move together as a unit, being pivotally connected at one point, and being interlatched at the other point.

Overload release or trip.-Fig. 1 to Fig. 3: When the bimetal 26 warps out from under the latching point of support l2, spring 2| biases the contact arm to pivot relative to the support l2, to the open circuit position of Fig. 3. The handle or support need not move, and thus, even if held, will not interfere with free movement or tripping of the contact arm. Parts 30 and end Ha of slot H provide stops for parts l8--i2.

Relatch.-Fig. 3 to Fig. 2: For l e-establishing the interlatched connection between the contact arm and the support it is merely necessary to rotate the support counterclockwise from the position of Fig. 3 to that of Fig. 2 so that the latchingrend of the support will catch up to the latching end of the contact arm and re-establish the interiatched connection between the parts. Contact arm I! is held by stop 30 during relatching; stop lib stops and holds the support after the handle has had sufllcient overtravel for reiatching.

Spring 2| imparts a biasing force simultaneously on the contact arm and the support at all times, and at all times tending to rotate them in opposite rotative directions, the support clockwise and the arm counterclockwise. This bias is inhibited, partially or wholly, by the various holds oi the various parts. Thus. when the parts are in the closed circuit position of Fig. 1. with the latch holding, the holding effect of the interlatch at 2! prohibits relative movement of the arm and support, and spring 2| biases the support, and with it the contact arm, in the closed circuit position so that the net effect 01' the spring at that time is to establish and maintain contact pressure at I 9-20.

When the holding eii'ect oi the latch disappears, as on overload, the bias of the spring is effective on the arm to cam it relative to the support, but is not effective to move the support, for the latter is held by the end I in of slot ll.

When the parts are in the open circuit positlo with the latch holding, the spring biases the contact arm against the stop 30 to hold the unit (arm and support) in such a way that the net efi'ect of the spring is to maintain the parts in the open circuit position of Fig. 2.

It will also be observed that the apex A is radially spaced from the axes so that the pressure point of the spring on the contact arm and support is spaced radiall from the axes to establish a moment arm for the contact arm and support about the axes.

The device here shown differs in principle from the device of the Morris and Lister Patent No. 1,071,566, Fig. 6, in that a single spring is used to provide all spring functions. The device hereof diilfers from the single spring device shown in a prior application of E. T. Platz, Serial No. 376,036, filed January '1, 1941, ,in that whereas the axes of rotation of the contact arm and support 01' the Platz device are spaced apart suificiently to permit the arm to rock on one or the other of the spaced pivots, selectively, in my device, the axes oi rotation are so located that the arm can not rock on either spaced pivot, selectively, but rather, the spring cams the arm and support simultaneously in opposite directions.

While the axes of rotation of the arm and support are shown as truly coincident, they need not be in coincidence, for a sufficient to permit the arm to rock selectively on the pivots, will not materially alter the mode of operation of the device here shown.

Now having described the device herein disclosed, reference should be had to the appended claims which determine the inventions hereof.

I claim:

1. In a circuit breaker, a manually actuable contact support mounted for rotation about an axis, a contact arm pivotally mounted thereon to rotate with respect thereto about an axis of rotation, and having at a contact point thereof a movable contact portion, a stationary contact to be engaged thereby, means releasably interlatching the support and contact arm at a latching point, the axes being between the arm contact point and the interlatch point, and a single spring taneously for biasing and indexing the support into and in its extreme positions, in one of which the contact arm contact is biased against the stationary contact for contact pressure, the spring also biasing the contact arm to move relative to the support on latch release for moving the contact thereof away from the stationary contact, the aforesaid axes being so spaced relative to each other that the arm cannot rock on either oi the two pivots, selectively, the spring, when the parts are in closed circuit position, and interlatched, biasing the arm to its closed circuit position, and at the same time biasing the support to its closed circuit position, and when the latch releases, while still biasing the support to its closed circuit position, biasing the arm out of its closed circuit position.

spacing of these axes, in-

engaging the contact arm and the support simul- 2. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes.

3. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, and means releasably interlatching said members so that they move as a unit when the latch holds, and move relatively when the latch releases.

4. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, one of the members having a stop portion, and a stationary abutment adapted to be engaged thereby for stopping the rotation of that member under spring bias, with the stopping point being radially spaced from the axis of that membar.

5. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions deflningsides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing bothsaid members in opposite rotative directions about the axes, one of the members having a contact por-- tion, and a stationary contact adapted to be engaged thereby for stopping the rotation of that member under spring bias, the contact makingpoint being radially spaced from the axis of that member.

6. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex members in opposite rotative directions about the axes, one of the members having a stop portion, and a stationary abutment adapted to be engaged thereby for stopping therotation of that member under spring bias, with the stopping point being radially spaced from the axis of that member, and means releasably interlatching and thus biasing both said said members so. that they move as a unit when the latch holds, and move relatively when the latch releases.

'7. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, one of the members having a stop portion, and a stationary abutment adapted to be engaged thereby for stopping the rotation of that member under spring bias, with the stopping point being radially spaced from the axis of that member, and means releasably interlatching said members so that they move as a unit when the latch holds, and move relatively when the latch releases, with the interlatching point being radially spaced from the axes.

8. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, one of the members having a stop portion, and two stationary abutments spaced in the direction of travel thereof, and between which the member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction.

9. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, each of the members having a stop portion, and two stationary abutments spaced in the direction of travel thereof, and between which the member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction.

10. In a circuit breaker, two pivoted members having portions extending in op osite radial directions from their pivotal axes, the portions defin n sides of an an le whose apex is remote from the axes. and a s ring means enga ing such portions in the a ex and thus biasing both said members in op osite rotative directions about the axes. each of the members having a stop portion,

and two stationary abutments spaced in the di-- rection of travel thereof, and between which the member rotates. with the member adapted to be en a ed thereby alternately for sto ping the rotation of that member under spring bias in either direction, the stop portion of one of the members being formed as a contact portion, and one of the abutments therefor also being formed as a contact portion.

11. In a circuit b eaker, two pivoted members having portions extendin in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, each of the members having a stop portion, and two stationary abutments spaced in the direction of travel thereof, and between which the 75 either of the W P S y,

member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction, the stop portion of one of the members being formed as a contact portion, and one of the'abutments therefor also being formed as a contact portion, and means releasably interlatching said members so that'they move as a unit when the latch holds, and move relatively when the latch releases.

12. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, each of the members having a stop portion, and two stationary abutments spaced in the direction of travel thereof, and between which the member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction, the stop portion of one of the membersbeing formed as a contact portion, and one of the abutments therefor also being formed as a contact portion, and means releasably interlatching said members so that they move as a unit when the latch holds, and move relatively when the latch releases, with the interlatchingpoint being radially spaced from the axes.

13. In a circuit breaker, two pivoted members, one of which is a manually actuable support, and the other of which is a contact arm, the members having portions extending in opposite radial directions from their axes defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and biasing both said portions in opposite rotative directions about the axes, and means releasably interlatching said members so that they move as a unit when the latch holds, and move relatively when the latch releases, with the interlatching point being radially spaced from the axes, each of the members having a stop portion,

and two stationary abutments spaced on opposite sides thereof, in the direction of travel thereof, and between which the member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction, the stop portion of one of the members being formed as a contact portion, and one of the abutments therefor, also being formed as a contact portion.

14. In a circuit breaker, a manually actuable contact support mounted for rotation about an axis, a contact arm pivotally mounted thereon to rotate with respect thereto about an axis of rotation, and having at a contact point thereof a movable contact portion, a stationary contact to be engaged thereby, means releasably interlatching the support and contact arm at a latching point, the axes being between the arm contact point and the interlatch point, and a single spring engaging the contact arm and the support simultaneously for biasing and indexing the support into and in its extreme positions, in one of which the contact arm contact is biased against the stationary contact for contact pressure, the spring also biasing the contact arm to move relative to the support on latch release for moving the contact thereof away from the stationary contact, the aforesaid axes being so spaced relative to each other that the arm can not rock on the spring,

when the parts are in closed circuit position, and interlatched, biasing the arm to its closed circuit position and at the same time biasing the support to its clbsed circuit position, and when the latch releases, while still biasing the support to its closed circuit position, biasing the arm out of its closed circuit position, the axes being concentric.

15. In a circuit breaker, two pivoted members having portions extending in opposite radial directions from their pivotal axes, the portions defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and thus biasing both said members in opposite rotative directions about the axes, the axes being concentric.

16. In a circuit breaker, two pivoteq members, one of which is a manually actuable support, and the other of which is a contact arm the members having portions extending in opposite radial directions from their axes, defining sides of an angle whose apex is remote from the axes, and a spring means engaging such portions in the apex and biasing both said portions in opposite rotative directions about the axes, and means releasably interlatching said members so that they move as a unit when the latch holds, and'move relatively when the latch releases, with the interlatching point being radially spaced from the axes, each of the members having a stop portion, and two stationary abutments spaced on opposite sides thereof, in the direction of travel thereof, and between which the member rotates, with the member adapted to be engaged thereby alternately for stopping the rotation of that member under spring bias in either direction, the stop portion of one of the members being formed as a contact portion, and one of the abutmentstherefor, also being formed as a axes being concentric.

WILLIAM H. FRANK.

contact portion the 

